Have you ever considered doing tighter integration with Jira. I have used Perforce and its integration, and it is really nice to be able to look up tickets by number or description and then select it.
Syncro SVN Client already provides integration with bug tracking tools. It works by setting SVN properties on the SVN repository which control the format of the bug ID included in the commit message that is recognized by the bug tracking tool. For JIRA integration you can use this JIRA plugin.